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Itchy rash in streaks or lines after being outdoors

Also called: Poison ivy, poison oak, plant rash

An itchy rash in streaks or lines with blisters after being outdoors is often poison ivy, oak, or sumac. It's caused by an oil on the plants and appears 12 to 72 hours after contact. It usually heals in 2 to 3 weeks.

Common causesPoison ivy, oak, or sumac
Usually serious?Usually not
Get checked ifRash on face or genitals, or widespread
If you think it's an emergency, call 911.Thinking about suicide? Call or text 988.

Overview

The oil (urushiol) causes an allergic skin reaction with red streaks, bumps, and blisters. Fluid in blisters doesn't spread it.

Burning these plants can cause lung irritation.

When to get medical care

Call 911Trouble breathing after burning plants.
Get care todayRash near eyes, mouth, or genitals. Widespread rash or swelling. Signs of infection.
See a doctor soonRash not improving after a week.

Causes

Causes include poison ivy, oak, sumac, and other plant irritants.

OwieClear has pages on 1 condition that can cause itchy rash in streaks or lines after being outdoors. Each shows how soon to get care.

Common causes

  • Poison ivy, oak, or sumac rashOften treated at home

    An itchy, red rash, often in streaks or lines with blisters, that shows up 12 to 48 hours after touching the plant's oil.

What you can do at home

  • Wash skin with soap and water right away.
  • Wash clothes and tools.
  • Use cool compresses and calamine.
  • Don't scratch.

Medicines

Antihistamines and hydrocortisone help. Severe cases may need steroid pills.

At the doctor

Diagnosed by exam.

Questions you may be asked

  • Outdoor exposure
  • Rash pattern

The exam

A skin exam.

Tests

  • None

Prevention

Avoid the plants.

  • Learn to identify them
  • Wear long sleeves

Check your symptoms

Most symptoms have more than one possible cause. The symptom checker looks at all of your symptoms together, plus your age, and shows how soon to get care.

Start the symptom checker

Sources

Last updated 2026-11-13.